This invention relates to a frame strip for receiving the edge of a sheet of material initially for use in securing the edge of a flexible or plastic sheet of transparent film but also usable in receiving the edge of a rigid sheet of transparent material such as glass or acrylic sheet.
Various forms of strip for securing the edge of a flexible sheet of transparent material have been proposed including those proposed by myself in, for example, my U.S. Pat. Nos. 3,982,306 and 3,999,258. These have been entirely satisfactory in that the flexible film is properly secured and remains taut across the space to be spanned despite the effects of wind flutter and expansion caused by temperature changes. The flexible or plastic films used can be acrylic or other plastics material or fibreglass sheeting. The films are normally used in a less expensive form of double glazing but can be used in greenhouse construction or any other area where the edge of a flexible sheet needs to be secured.
However, the above types of fixing strips have the disadvantage that a cut raw edge of the sheet or film is left exposed leaving an untidy appearance which is particularly detrimental in comparison with double glazing using rigid glass or acrylic sheet.
In addition, while various arrangements of strip have been proposed for securing different thicknesses of film or sheet, none of the proposals have allowed the flexible sheet to be replaced by a rigid sheet of glass or acrylic or for a combination of rigid and flexible sheets to be employed. Thus, at any stage if a user wishes to replace the flexible sheets by a rigid sheet arrangement, it has been necessary to totally remove and replace the securing arrangements which obviously is a costly exercise.